Two Red Cross drivers held for almost two weeks in Sudan's troubled Darfur region were safely released on Sunday, their organisation said.
They were among eight Sudanese employees of the International Committee of the Red Cross detained by gunmen on August 26 as they travelled between Nertiti and Zalingei in Central Darfur state.
Six were soon freed but the drivers continued to be held.
"Our two remaining colleagues have also been released and they have returned to Zalingei," Rafiullah Qureshi, the ICRC's spokesman in Sudan, told AFP.
He said they were tired but well.
The drivers were probably detained to operate the vehicles, which are different from trucks ordinarily found in Darfur, Quereshi said.
Contacts are continuing with tribal, government, military and other officials in the area in order to get back the trucks which are "crucial" to Red Cross operations, he added.
In addition to aid work the ICRC, as a neutral intermediary, has facilitated the handover and repatriation of numerous prisoners held by groups in Darfur.
Rebels fighting for a decade against the government in Sudan's far-west have detained soldiers and others.
Government-linked militia and paramilitary groups are also suspected to have carried out many kidnappings, carjackings and other crimes in the region.
Analysts say Sudan's crisis-hit regime now has less money for militias it deployed against the insurgency, and the militias are acting outside government control.